If you are getting errors during export, please check the following:
1. Make sure you have plenty of storage space available on your iPhone or iPad (in the Settings app, go to General, Storage & iCloud Usage)
2. Try creating a simple project with one or two clips, and export at 1080p, with the Economy quality setting. If even that doesn't work, we recommend closing all background apps, and restarting your iPhone or iPad.
3. If after verifying storage, and restarting your iPhone or iPad, you're still unable to export, please contact us in the forums or at email@example.com